1. Field of the Invention
The present invention relates generally to air compressors used on locomotives to supply pressurized air to the brakes of the locomotives and all other pneumatic systems on the locomotive and, more particularly, to a temperature management system for an air compressor to maintain the compressor at a controlled temperature during operation.
2. Description of Related Art
Air compressors are used on freight, passenger, and switcher locomotives for supplying compressed air to the locomotive, train brake operation, and all other pneumatic systems on the locomotive. Due to the operating nature of a multiple stage compressor with inter-stage cooling, the internal temperatures of the compressor must be held high enough to avoid the internal condensation of water. On the other hand, too little cooling will cause the compressor to be less efficient and in the extreme case, will lead to compressor failure. In order to maintain a proper operating temperature, air compressors are typically located directly beneath the locomotive radiator fans for overheating protection and minimum compressor operating temperatures are maintained by never turning the compressor off when in use. In other words, current air compressors are typically operated in a load/unload method of operation. However, positioning air compressors directly beneath the locomotive radiator fan is not always an ideal location for the air compressor. In addition, since the air compressor is never turned off, power is unnecessarily wasted.
In addition, systems and control circuits are known for controlling the operation of a fan-cooled aftercooler receiving pressurized air from a compressor located in a locomotive. For instance, U.S. Pat. No. 5,894,881 to Wagner et al. discloses such a control circuit. However, the system disclosed in this patent is provided to prevent the aftercooler from pulling ambient air past finned heat exchanger tubes receiving compressed air from the compressor when the ambient temperature is at or below freezing. Such a system is not used to manage the temperature of the compressor and, therefore, does not allow the repositioning of a compressor in any suitable location in the locomotive.
Accordingly, a need exists for an air compressor utilizing an independent temperature management system, thereby removing the need for mounting the air compressor directly in the proximity of the locomotive radiator or other cooling fans. A further need exists for an air compressor that has a system for removing the need for mounting the air compressor directly hi the proximity of the locomotive radiator or other cooling fans.